AN ASSESSMENT OF AERIALLY APPLIED ASULAM AS A METHOD OF LONG-TERM BRACKEN CONTROL

The vegetation of 117 bracken-dominated sites that had been sprayed wi th asulam from the air over a wide range of dates was recorded. There is a high variability in initial efficacy and sites displayed consider able differences in regeneration in the years following treatment. Sit es treated more than 10 years previously all showed good control of br acken. The absence of sites where bracken has regenerated completely w as attributed to either respraying at a later date or the poor records kept of previous unsuccessful control measures. There was also a high degree of variation in the amount and type of herbaceous vegetation p resent below untreated bracken. The data presented suggest that aerial spraying of bracken with asulam can be a long-term and cost-effective control method. However; in the light of experimental results from ot her studies, the success of an individual operation is critically depe ndent on the initial efficacy of treatment, the initial floristic comp osition (if any) and suitable follow-up management (C) 1998 Academic P ress.